Book jacket
Doktor Proktor i ego volshebnyĭ poroshok
(Доктор Проктор и его волшебный порошок)


A mysterious postcard leads Lisa and Nilly from Oslo to Paris in search of Doctor Proctor but, once there, all they find of their missing friend is a time-traveling bathtub powered by a special soap and several sinister individuals determined to do all they can to locate the eccentric inventor.